Unique negatives taken by Captain Scott on his ill-fated polar expedition have been saved for the nation after a major fund-raising campaign.

The Polar Museum at the Scott Polar Research Institute (SPRI) in Cambridge had to raise £275,000 by the end of this month to avoid the prospect of the 113 negatives being sold at auction, probably to a foreign bidder.

The negatives are described as an "extraordinary visual record" of Scott's famous 1912 Terra Nova Expedition in which he and his four companions died on their return from being beaten to the South Pole by Norwegian Roald Amundsen.

Today the institute announced that it had successfully reached its target after being awarded a grant of £233,450 from the National Heritage Memorial Fund (NHMF), in addition to funds already raised through a public appeal spearheaded by Sir Ranulph Fiennes.

Sir Ranulph said: "Scott's negatives can now take their rightful place in Cambridge alongside the camera on which they were taken, as well as the remaining Scott and Herbert Ponting prints - all of which speak so powerfully to us of the courage and sacrifice of those on the British Antarctic Expedition.

"The negatives have been recently rediscovered, having been thought lost.

"If the Scott Polar Research Institute had not been successful then there was every chance that they would have been sold abroad and into a private collection."

Dame Jenny Abramsky, chairman of the NHMF, said the images provide an extraordinary insight into the rigours of his epic but ultimately doomed expedition.

"As precious as the corresponding original prints, these negatives record not only day-to-day life in the Antarctic but also the development of Scott's photographic skills," she added.

The negatives had been in a private collection and only emerged in 2012, having been thought lost.

The museum, which has no budget for acquisitions, said this was the only chance a museum in the United Kingdom has of acquiring this extraordinary visual record.

The negatives are a record of Scott's earliest attempts - under the guidance of expedition photographer Ponting - through to his unparalleled images of his team on the southern journey.

Professor Julian Dowdeswell, SPRI director, said: "The overwhelming level of support and assistance from the public and from charitable trusts and bodies has helped The Scott Polar Research Institute purchase this extraordinary visual record of Scott's last heroic expedition.

"As part of the University of Cambridge, SPRI will ensure that these negatives are cared for to the highest possible standards and, once digitised, we will ensure that these resources will be within reach of a worldwide audience."

Following a period of conservation and research, the museum plans to hold a public exhibition of the images.